This invention pertains to sealing arrangements for rotating mechanisms, and relates more particularly to an improved mounting configuration for the rotating portion of a seal as utilized in high temperature, high speed turbo-machinery.
Certain sealing arrangements for rotating elements such as high speed rotary shafts, include rotating and non-rotating sealing elements which have relatively rotating surfaces in sealing interengagement. The rotating portion of the seal, herein referred to as a seal rotor, is secured for rotation with the rotating element, while the nonrotating sealing element is typically affixed to the surrounding housing to which the rotating shaft may be journaled.
Care must be taken in securing the seal rotor to the rotating element to maintain an effective sealing interengagement with the nonrotating portion of the seal. While in many applications the problem can be approached by utilization of a "soft mount" such as an elastomeric seal configuration, such is not applicable to certain situations particularly wherein very high temperatures and other extreme operational environments occur. This is characteristic, for example, of gas turbo-machinery wherein soft mount members such as elastomerics are not capable of withstanding the harsh environment. Other prior art arrangements such as utilization of resilient mounts oftentime require extensive axial space.
A particular problem of the nature described is a tendency towards distortion of the sealing face of the seal rotor as a result of the forces required to secure the seal rotor to the rotating shaft. Some sources of such distortion are the manufacturing imperfections associated with the mounting structure securing of the seal rotor to the shaft. For example, in a gas turbine engine the substantial axial clamping force, on the order of many thousands of pounds per square inch, can induce waviness or other non-axisymmetric distortions into the sealing face of the seal rotor by virtue of the transmittal of the clamping force from the necessarily imperfectly manufactured clamping mechanism into the seal rotor itself.